Correct iOS build for latest Xcode beta.

base/ios/crb_protocol_observers_unittest.mm

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "base/ios/crb_protocol_observers.h"
 #include "base/ios/weak_nsobject.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/mac/scoped_nsobject.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/gtest_mac.h"
@@ skipping 18 matching lines @@
 @interface TestPartialObserver : NSObject<TestObserver>
 @property(nonatomic, readonly) BOOL requiredMethodInvoked;
 @end
 
 // Implements all the methods in the TestObserver protocol.
 @interface TestCompleteObserver : TestPartialObserver<TestObserver>
 @property(nonatomic, readonly) BOOL optionalMethodInvoked;
 @end
 
 @interface TestMutateObserver : TestCompleteObserver
-
+- (instancetype)init NS_UNAVAILABLE;
 - (instancetype)initWithObserver:(CRBProtocolObservers*)observer
     NS_DESIGNATED_INITIALIZER;
 
 @end
 
 namespace {
 
 class CRBProtocolObserversTest : public PlatformTest {
  public:
   CRBProtocolObserversTest() {}
@@ skipping 201 matching lines @@
   [super reset];
   _optionalMethodInvoked = NO;
 }
 
 @end
 
 @implementation TestMutateObserver {
   __weak id _observers;
 }
 
+- (instancetype)init {
+  NOTREACHED();
+  return nil;
+}
+
 - (instancetype)initWithObserver:(CRBProtocolObservers*)observers {
   self = [super init];
   if (self) {
     _observers = observers;
   }
   return self;
 }
 
 - (void)mutateByAddingObserver:(id<TestObserver>)observer {
   [_observers addObserver:observer];
 }
 
 - (void)mutateByRemovingObserver:(id<TestObserver>)observer {
   [_observers removeObserver:observer];
 }
 
 - (void)nestedMutateByAddingObserver:(id<TestObserver>)observer {
   [_observers mutateByAddingObserver:observer];
 }
 
 - (void)nestedMutateByRemovingObserver:(id<TestObserver>)observer {
   [_observers mutateByRemovingObserver:observer];
 }
 
 @end